Reactive shoe

ABSTRACT

This invention relates generally to footwear and methods for making the same, and more particularly to an athletic shoe with a reactive midsole. In one aspect of the invention, the midsole provides a continuously increasing offset between a heel center of pressure and a ball-of-foot center of pressure between the loading and a toe off gait phases.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/684,563, entitled “REACTIVE SHOE” filed on Aug. 17,2012, the entire disclosure of which is incorporated by referenceherein. This application also cross-references the following U.S. Designpatent application Ser. Nos. 29/428,044, 29/428,045, 29/428,047,29/428,049, 29/428,051 and 29/428,052, all filed Jul. 25, 2012 and allentitled “Shoe Sole,” the entire disclosures of which are allincorporated by reference herein.

FIELD

This disclosure relates to a midsole for footwear, more particularly toa reactive midsole having a dynamic offset.

BACKGROUND

Athletic footwear ideally provides protection from injury whileenhancing performance. Generally, athletic footwear comprises an upperportion and a sole portion. The upper portion at minimum secures thefootwear to the user's foot and attaches to the sole. The soletraditionally comprises a midsole and an outsole. The outsole contactsthe ground and commonly has wear-resistant and slip-resistantproperties. The midsole cushions the foot against forces imparted by theground while walking or exercising. In the case of running, the midsoleis particularly important for absorbing ground impact forces transferredto the foot, leg and body, and because it may influence the runner'sgait. For a general description of human gait and running gait inparticular, see “Biomechanics and Analysis of Running Gait,” Duagn etal, Physical Medicine and Rehabilitation Clinics of North America, 16(2005), herein incorporated by reference in its entirety.

Traditional running shoes are designed with midsoles focused onmitigating ground forces translated to the runner via the foot, or oninfluencing the runner's gait. For example, U.S. Pat. No. 5,678,327 toHalberstadt discloses an athletic shoe incorporating a cushioning andgait-adapting device which provides resilient cushioning while adaptingto the gait of the user during running and other athletic activities.The shoe comprises an upper and a sole with the sole having a heel withmedial and lateral ground-engaging elements. A cushioning and energyreturn and gait-adapting device is provided and comprises a supportstructure and one or more spring devices. Each spring device has agenerally U-shaped pivot or swivel section and lateral and medialresiliently flexible pods. The pivot section has a mid-portion which issupported by the pivot cradle of the support structure. Resilientflexing of the lateral pod responsive to weight-bearing forces causesreaction forces to be applied across to the medial pod which is thencaused to flex so that the medial pod is brought into an orientation forcontact with the ground. Halberstadt is incorporated by reference forall purposes.

Also, U.S. Pat. No. 7,076,892 to Meschan discloses a shoe including aplate capable of being deflected in a direction substantiallyperpendicular to the major longitudinal axis of the shoe, an arch bridgeintegral with the plate, and at least one inflated cushion spaced apartfrom the plate during the entire walking gait cycle of the wearer,during the entire running gait cycle of the wearer, when the shoe is inan unloaded state and at all other times. Meschan is incorporated byreference for all purposes.

Some running shoe designs focus on particular types of running gaits,for example U.S. Pat. No. 8,166,672 to Murphy (“Murphy”) focuses onmidfoot strikers. Murphy discloses a shoe sole for a running shoeconducive to a midfoot striking gait including a cushioning elementpositioned between the upper surface and the ground-contacting surface,at least a portion of which is positioned on a lateral side of the soleand contained within a region between 15% and 90% of the length of theshoe sole as measured from a rearfoot end of the sole. One or more highabrasion-resistant ground-contacting crash pads are positioned below thecushioning element, and include a lateral side portion contained withina region extending a distance of 20% the length of the shoe sole, asmeasured from a rearfoot end of the shoe sole. The shoe sole, preferablydevoid of at least vertical arch sculpting, also includes a longitudinalflex groove positioned just medial of the crash pads. Murphy isincorporated by reference for all purposes.

Furthermore, some recent efforts have been made to design running shoeswith enhanced resilient features, such as U.S. Patent Publication No.2011/0138652 to Lucas (“Lucas”). Lucas discloses a shoe which includes asole plate having in a forefoot area and a plurality of leaf springelements, wherein the sole plate and the plurality of leaf springelements are manufactured as a single piece. Each of the plurality ofleaf spring elements has one free end not connected with the sole plate.Lucas is incorporated by reference for all purposes. Similar designs toLucas include U.S. Patent Publication No. 2009/0178303 to Hurd (“Hurd”)and U.S. Patent Publication No. 2008/0034615 to Nishikawa (“Nishikawa”),both of which are incorporated by reference for all purposes.

However, the conventional designs do not appreciably if at all influencethe loading dynamics of a runner's heel center of pressure and aball-of-foot center of pressure, or combinations thereof, during thephases of engagement with the ground. That is, for example, duringinitial ground contact through to loading, transition and toe offphases.

Conventional running shoes use a static offset midsole. That is, themidsole thickness at a given point generally remains constant or static,albeit with some compression due to pressures and forces between therunner's foot and the ground.

What is needed is an athletic shoe with a reactive midsole. For example,a reactive midsole that provides a continuously increasing offsetbetween a heel center of pressure and a ball-of-foot center of pressurebetween the loading and a toe off gait phases.

SUMMARY OF THE INVENTION

It is one aspect of the present invention to provide an athletic shoewith a reactive midsole that provides an increasing offset between aheel center of pressure and a ball-of-foot center of pressure betweenthe loading and a toe off gait phases. Such a midsole creates a dynamicoffset and, among other things, provides a smoother and more efficientrunning experience. In some embodiments, the midsole comprises a firstportion adjacent the heel and a second portion, interconnected to thefirst, of generally decreasing thickness, in which the first portion isof equal or less total distance of the longitudinal axis of the midsole.In some embodiments, a foot center of pressure imparted to the midsolecontinuously increases between the loading gait phase and the toe offgait phase.

Although many of the embodiments are focused on athletic footwear, otherapplications are available. Such applications include activities inwhich one or more of increased footwear performance, increased athleticperformance and increased comfort is desired.

Furthermore, the concepts disclosed with respect to footwear andfootwear midsoles may be applied to footwear styles that arespecifically designed for a variety of other athletic activities,including basketball, baseball, football, soccer, walking, and hiking,for example, and may also be applied to various non-athletic footwearstyles. Accordingly, one skilled in the relevant art will recognize thatthe concepts disclosed herein may be applied to a wide range of footwearstyles and are not limited to the specific embodiments discussed belowand depicted in the figures.

The concepts also may be applied to footwear styles that are generallyconsidered to be non-athletic, including dress shoes, loafers, sandals,and work boots. The concepts disclosed herein apply, therefore, to awide variety of footwear styles. Also, aspects of this invention may beused in conjunction with other portions of a footwear structure, such asthe outsole and insole.

As used herein, the term “a” or “an” entity refers to one or more ofthat entity. As such, the terms “a” (or “an”), “one or more” and “atleast one” can be used interchangeably herein. It is also to be notedthat the terms “comprising”, “including”, and “having” can be usedinterchangeably.

As used herein, “at least one”, “one or more”, and “and/or” areopen-ended expressions that are both conjunctive and disjunctive inoperation. For example, each of the expressions “at least one of A, Band C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “oneor more of A, B, or C” and “A, B, and/or C” means A alone, B alone, Calone, A and B together, A and C together, B and C together, or A, B andC together.

As used herein, the term, “innersole” refers to a removable portion ofthe sole of an article of footwear, which is inserted into the articleof footwear from the opening in the upper and which is designed toprovide support to the wearer's foot, depending upon the wearer'sanatomy and the intended use of the article of footwear.

As used herein, the term, “midsole” refers to that portion of the soleof an article of footwear sandwiched between the innersole and theoutsole, to which is attached the outsole.

As used herein, the term, “outsole” refers to that portion of the soleof an article of footwear that is furthest from the upper.

As used herein, the term, “upper” refers to any portion of the shoeabove the sole.

As used herein, the terms “shoe” and “footwear” refer to an article tobe worn by a user's foot.

As used herein, “gait” is the pattern of movement of the limbs duringlocomotion over a solid surface.

As used herein, “foot strike” is how the foot strikes the ground, whichmay be via the heel, midfoot or forefoot.

In one embodiment, a article of footwear is disclosed, the article offootwear comprising: an upper attachable to a foot of a user; and amidsole connected to the upper comprising a first portion proximate aheel of the foot and a second portion proximate a ball-of-foot of thefoot, the heel of the foot having a heel center of pressure imparted tothe first portion and defining a first distance between the heel centerof pressure and the ground, and a ball-of-foot center of pressureimparted to the second portion and defining a second distance betweenthe ball-of-foot center of pressure and the ground, wherein a distanceoffset of the first distance minus the second distance is increasedbetween a loading gait phase and a toe off gait phase.

The first portion may be generally of constant thickness and the secondportion may generally be of decreasing thickness along a longitudinalaxis of the midsole from the heel to the ball-of-foot. The first portionmay be 30-50% of a total distance of the longitudinal axis of themidsole. The first portion may be interconnected to the second portion.The decreasing thickness of the second portion may generally form acurve, such as a French curve, a compound curve, a uniform curve or arc,an S-shaped curve, a continuous curve and a discontinuous curve. Thedistance offset may always be positive between the loading gait phaseand the toe off gait phase. The distance offset at the toe off gaitphase may be at least 40 mm. The distance offset of the first distanceminus the second distance may continuously increase between the loadinggait phase and the toe off gait phase. A foot center of pressureimparted to the midsole may continuously increase between the loadinggait phase and the toe off gait phases.

In another embodiment, a method of manufacturing an article of footwearis disclosed, the method comprising: forming an upper attachable to afoot of a user; and forming a midsole connected to the upper comprisinga first portion proximate a heel of the foot and a second portionproximate a ball-of-foot of the foot, the heel of the foot having a heelcenter of pressure imparted to the first portion and defining a firstdistance between the heel center of pressure and the ground, and aball-of-foot center of pressure imparted to the second portion anddefining a second distance between the ball-of-foot center of pressureand the ground, wherein a distance offset of the first distance minusthe second distance is increased between a loading gait phase and a toeoff gait phase.

In a further embodiment, an athletic shoe is disclosed, the athleticshoe comprising: an upper attachable to a foot of a user; and a midsoleconnected to the upper comprising a first portion generally of constantthickness proximate a heel of the foot and a second portion generally ofdecreasing thickness along a longitudinal axis of the midsole from theheel to the ball-of-foot and proximate a ball-of-foot of the foot, thefirst portion 30-50% of a total distance of the longitudinal axis of themidsole and interconnected to the second portion, the heel of the foothaving a heel center of pressure imparted to the first portion anddefining a first distance between the heel center of pressure and theground, and a ball-of-foot center of pressure imparted to the secondportion and defining a second distance between the ball-of-foot centerof pressure and the ground, wherein a distance offset of the firstdistance minus the second distance is continuously increased between aloading gait phase and a toe off gait phase and is always positivebetween the loading gait phase and the toe off gait phase.

In yet another embodiment, an article of footwear is disclosedcomprising: an upper attachable to a foot of a user; a midsole connectedto the upper comprising a first portion proximate a heel of the foot anda second portion proximate a ball-of-foot of the foot; and an outsoleconnected to the midsole comprising a central portion, a medial portionand a lateral portion, the medial portion and the lateral portionforming a substantially non-smooth surface, the central portion forminga substantially smooth surface with a curvilinear edge. Further, in oneembodiment, the central portion is of a first material and the medialand lateral portions are of a second material. In one embodiment, thecentral portion extends over and is integral to at least one of a toeportion and a heel portion of the article of footwear.

The preceding is a simplified summary of the invention to provide anunderstanding of some aspects of the invention. This summary is neitheran extensive nor exhaustive overview of the invention and its variousembodiments. It is intended neither to identify key or critical elementsof the invention nor to delineate the scope of the invention but topresent selected concepts of the invention in a simplified form as anintroduction to the more detailed description presented below. As willbe appreciated, other embodiments of the invention are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below.

The present disclosure, in various embodiments, configurations, oraspects, includes components, methods, processes, systems and/orapparatus substantially as depicted and described herein, includingvarious aspects embodiments, configurations, sub-combinations, andsubsets thereof. Those of skill in the art will understand how to makeand use the various aspects, embodiments, configurations,sub-combinations, and subsets of the present disclosure afterunderstanding the disclosure. The present disclosure, in variousaspects, embodiments, and configurations, includes providing devices andprocesses in the absence of items not depicted and/or described hereinor in various aspects, embodiments, or configurations hereof, includingin the absence of such items as may have been used in previous devicesor processes, e.g., for improving performance, achieving ease and\orreducing cost of implementation.

The foregoing discussion of the disclosure has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the disclosure to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of thedisclosure are grouped together in one or more aspects, embodiments, orconfigurations for the purpose of streamlining the disclosure. Thefeatures of the aspects, embodiments, or configurations of thedisclosure may be combined in alternate aspects, embodiments, orconfigurations other than those discussed above. This method ofdisclosure is not to be interpreted as reflecting an intention that theclaims require more features than are expressly recited in each claim.Rather, as the following claims reflect, inventive aspects lie in lessthan all features of a single foregoing disclosed aspect, embodiment, orconfiguration. Thus, the following claims are hereby incorporated intothis Detailed Description, with each claim standing on its own as aseparate preferred embodiment.

Moreover, though the description of the disclosure has includeddescription of one or more aspects, embodiments, or configurations andcertain variations and modifications, other variations, combinations,and modifications are within the scope of the invention, e.g., as may bewithin the skill and knowledge of those in the art, after understandingthe present disclosure. It is intended to obtain rights which includealternative aspects, embodiments, or configurations to the extentpermitted, including alternate, interchangeable and/or equivalentstructures, functions, ranges or steps to those claimed, whether or notsuch alternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of thespecification to illustrate several examples. These drawings, togetherwith the description, explain the principles of the invention(s). Thedrawings simply illustrate preferred and alternative examples of how theinvention(s) can be made and used and are not to be construed aslimiting the invention(s) to only the illustrated and describedexamples.

Further features and advantages will become apparent from the following,more detailed, description of the various embodiments of theinvention(s), as illustrated by the drawings referenced below.

FIG. 1A is a side view of a user fitted with one embodiment of thereactive shoe during the initial ground contact gait portion;

FIG. 1 b is a side view of a user fitted with one embodiment of thereactive shoe during the loading gait portion;

FIG. 1 c is a side view of a user fitted with one embodiment of thereactive shoe during the transition gait portion;

FIG. 1 d is a side view of a user fitted with one embodiment of thereactive shoe during the toe off portion;

FIG. 2 a is a left elevation view of a portion of one embodiment of thereactive shoe;

FIG. 2 b is a bottom perspective view of one embodiment of the reactiveshoe;

FIG. 2 c is a right elevation view of a portion of one embodiment of thereactive shoe;

FIG. 2 d is a front elevation view of one embodiment of the reactiveshoe;

FIG. 2 e is a rear elevation view of one embodiment of the reactiveshoe;

FIG. 3 is a right elevation view of a portion of one embodiment of thereactive shoe;

-   -   Example A1 illustrates a lateral elevation view of a portion of        an example construction of a particular embodiment of the        reactive shoe of Example A2—the drawing is to scale with        dimensions in millimeters;    -   Example A2 illustrates a bottom perspective view of a portion of        an example construction of a particular embodiment of the        reactive shoe—the drawing is to scale with dimensions in        millimeters;    -   Example A3 illustrates a medial elevation view of a portion of        an example construction of a particular embodiment of the        reactive shoe of Example A2—the drawing is to scale with        dimensions in millimeters;    -   Example A4 illustrates a detailed view of Section A-A′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A5 illustrates a toe (i.e. front) elevation view of a        portion of an example construction of a particular embodiment of        the reactive shoe of Example A2—the drawing is to scale with        dimensions in millimeters;    -   Example A6 illustrates a heel (i.e. rear) elevation view of a        portion of an example construction of a particular embodiment of        the reactive shoe of Example A2—the drawing is to scale with        dimensions in millimeters;    -   Example A7 illustrates a detailed view of Section B-B′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A8 illustrates a detailed view of Section C-C′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A9 illustrates a detailed view of Section D-D′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A10 illustrates a detailed view of Section E-E′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A11 illustrates a detailed view of Section F-F′ of        Example A2—the drawing is to scale with dimensions in        millimeters;    -   Example A12 illustrates a detailed view of Section G-G′ of        Example A2—the drawing is to scale with dimensions in        millimeters; and    -   Example A13 illustrates a table of dimensions identified in        Examples A1-A4 with respect to shoe size—the dimensions are in        millimeters.

It should be understood that the drawings are not necessarily to scale.In certain instances, details that are not necessary for anunderstanding of the invention or that render other details difficult toperceive may have been omitted. It should be understood, of course, thatthe invention is not necessarily limited to the particular embodimentsillustrated herein.

DETAILED DESCRIPTION

The present disclosure relates generally to footwear and methods formaking the same, and more particularly to an athletic shoe with areactive midsole. In one aspect of the invention, the midsole providesan increasing offset between a heel center of pressure and aball-of-foot center of pressure between the loading and a toe off gaitphases.

In the following description, and for the purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the various aspects of the invention. It will beunderstood, however, by those skilled in the relevant arts, that thepresent invention may be practiced without these specific details. Inother instances, known structures and devices are shown or discussedmore generally in order to avoid obscuring the invention. In many cases,a description of the operation is sufficient to enable one to implementthe various forms of the invention, particularly when the operation isto be implemented in software. It should be noted that there are manydifferent and alternative configurations, devices and technologies towhich the disclosed inventions may be applied. The full scope of theinventions is not limited to the examples that are described below.

The following description will typically be with reference to specificstructural embodiments and methods. It is to be understood that there isno intention to limit the invention to the specifically disclosedembodiments and methods but that the invention may be practiced usingother features, elements, methods and embodiments. Preferred embodimentsare described to illustrate the present invention, not to limit itsscope, which is defined by the claims. Furthermore the embodiments ofdiscussed may be combined with any one or more other embodimentsdescribed explicitly or impliedly herein. Those of ordinary skill in theart will recognize a variety of equivalent variations on the descriptionthat follows. Like elements in various embodiments are commonly referredto with like reference numerals.

Referring now to FIGS. 1-3, several representations and configurationsof the present invention are shown. In regard to FIGS. 1 a-d, oneembodiment of a reactive shoe is depicted as worn by a user through fourgait phases. That is, FIG. 1 a depicts a user in the initial groundcontact gait portion (state a), FIG. 1 b in the loading gait portion(state b), FIG. 1 c in the transition gait portion (state c) and FIG. 1d in the toe off portion (state d). A leg 20 of a user with foot 22,toes 24, ball-of-foot 26, arch 28 and heel 30 is depicted as fitted toshoe 100 while in locomotion (e.g. walking or running) along ground 10.With regards to FIGS. 1-3, shoe 100 comprises shoe upper 110, shoe upper110, shoe forefoot 120, shoe heel portion 130, shoe lateral portion 140,shoe medial portion 150, shoe outsole 160 and shoe midsole 170. Shoeoutsole 160 comprises shoe outsole thickness 162, shoe outsole nominaltraction pattern 164, and shoe outsole S-wave pattern 166. Shoe midsole170 comprises shoe midsole exterior upper edge 172 and shoe midsoleinterior upper edge 174.

With respect to FIGS. 1 a-d, an axis of center of pressure—heel CP_(h)and an axis of center of pressure—ball-of-foot CP_(bf) are shown. Eachof these axes are parallel to the ground 10 and extend laterally withrespect to shoe 100. Each of these axes run through their respectivepoints of center of pressure, as defined by a point through which acenter of pressure is formed by the ball-of-foot and the heel of a user.Stated another way, in the case of the heel of a user, the heel forms asurface that presses against the inside of the shoe 100 and receives anupward force from the ground 10; that heel surface thus undergoes aforce over the heel surface area, i.e. a pressure, which may bekinematically translated to a center of pressure point. These twopressure points, i.e. heel center of pressure point and ball-of-footcenter of pressure point, may by kinematically combined to form onecenter of pressure (COP) for the entire foot 22 of the user.

The axis of center of pressure—heel CP_(h) will define a distance to theground 10 as the user translates along ground 10. Similarly, the axis ofcenter of pressure—ball-of-foot CP_(bf) will define a distance to theground 10 as the user translates along ground 10. More specifically, asshown in FIG. 1 a, when the user is in an initial ground contact gaitportion (state a), the axis of center of pressure—heel CP_(h) defines adistance to heel D_(h-a) and the axis of center of pressure—ball-of-footCP_(bf) defines a distance to ball-of-foot D_(bf-a). Similarly, as shownin FIG. 1 b, when the user is in the loading gait portion (state b), theaxis of center of pressure—heel CP_(h) defines a distance to heelD_(h-b) and the axis of center of pressure—ball-of-foot CP_(bf) definesa distance to ball-of-foot D_(bf-b). As shown in FIG. 1 c, when the useris in a transition gait portion (state c), the axis of center ofpressure—heel CP_(h) defines a distance to heel D_(h-c) and the axis ofcenter of pressure—ball-of-foot CP_(bf) defines a distance toball-of-foot D_(bf-c). Finally, as shown in FIG. 1 d, when the user isin an initial ground contact gait portion (state d), the axis of centerof pressure—heel CP_(h) defines a distance to heel D_(h-d) and the axisof center of pressure—ball-of-foot CP_(bf) defines a distance toball-of-foot D_(bf-d).

It should be noted that each of the axis of center of pressure—heelCP_(h) and the axis of center of pressure—ball-of-foot CP_(bf) aredisposed at an interface of the respective heel 30 and ball-of-foot 26and the inside bottom of the shoe 100. In FIGS. 1 a-d, this interface isdepicted to reside opposite the upper edge of the midsole 170. However,in some embodiments, the midsole 170 is not of uniform height, andinstead, as shown in FIG. 3, comprises a shoe midsole exterior upperedge 172 and a shoe midsole interior upper edge 174. In such anembodiment, the axis of center of pressure—heel CP_(h) and the axis ofcenter of pressure—ball-of-foot CP_(bf) are disposed at an interface ofthe respective user heel and user ball-of-foot and shoe midsole interiorupper edge 174. Further, in some embodiments an insole resides on top ofthe midsole 170, wherein the axis of center of pressure—heel CP_(h) andthe axis of center of pressure—ball-of-foot CP_(bf) are disposed at aninterface of the respective user heel and user ball-of-foot and uppersurface of insole.

The difference between the distance to heel and the distance toball-of-foot at any particular gait portion is the offset. For example,as shown in FIG. 1 b, the offset is defined as distance to heel D_(h-b)minus distance to ball-of-foot D_(bf-b).

In one embodiment, the offset when the shoe 100 is in the loading gaitportion (state b) is between 0.1 and 5 mm. In a more preferredembodiment, the offset when the shoe 100 is in the loading gait portion(state b) is between 0.1 and 4 mm. In a most preferred embodiment, theoffset when the shoe 100 is in the loading gait portion (state b) isbetween 0.1 and 3 mm.

In one embodiment, the offset when the shoe 100 is in the loading gaitportion (state b) is approximately 1 mm.

In one embodiment, the offset when the shoe 100 is in the transitiongait portion (state c) is between 2 and 10 mm. In a more preferredembodiment, the offset when the shoe 100 is in the transition gaitportion (state c) is between 3 and 9 mm. In a most preferred embodiment,the offset when the shoe 100 is in the transition gait portion (state c)is between 4 and 9 mm.

In one embodiment, the offset when the shoe 100 is in the transitiongait portion (state c) is approximately 6 mm.

In one embodiment, the offset when the shoe 100 is in the toe offportion (state d) is between 5 and 60 mm. In a more preferredembodiment, the offset when the shoe 100 is in the toe off portion(state d) is between 10 and 55 mm. In a most preferred embodiment, theoffset when the shoe 100 is in the toe off portion (state d) is between10 and 50 mm.

In one embodiment, the offset when the shoe 100 is in the toe offportion (state d) is approximately 45.5 mm.

In one embodiment, the value of the distance of the axis of center ofpressure—heel CP_(h) and the bottom of the midsole below the axis ofcenter of pressure—heel CP_(h) minus the distance of the axis of centerof pressure—ball-of-foot CP_(bf) and the bottom of the midsole below theaxis of center of pressure—ball-of-foot CP_(bf) is between 0.1 mm and 10mm throughout a user's gait. In a more preferred embodiment, thisdistance is between 0.1 mm and 9 mm. In a most preferred embodiment,this distance is between 1 and 7.5 mm. In one embodiment, this distanceis between 1 and 4.5 mm. In another embodiment, this distance is between4 and 7.5 mm.

In one embodiment, the value of the distance of the axis of center ofpressure—heel CP_(h) and the bottom of the midsole below the axis ofcenter of pressure—heel CP_(h) minus the distance of the axis of centerof pressure—ball-of-foot CP_(bf) and the bottom of the midsole below theaxis of center of pressure—ball-of-foot CP_(bf) is between 0.1 mm and 6mm at initial ground contact gait portion (state a). In a more preferredembodiment, this distance is between 0.1 mm and 9 mm. In a mostpreferred embodiment, this distance is between 0.5 and 8 mm. In oneembodiment, this distance is approximately 1 mm. In another embodiment,this distance is approximately 4 mm.

In one embodiment, the value of the distance of the axis of center ofpressure—heel CP_(h) and the bottom of the midsole below the axis ofcenter of pressure—heel CP_(h) minus the distance of the axis of centerof pressure—ball-of-foot CP_(bf) and the bottom of the midsole below theaxis of center of pressure—ball-of-foot CP_(bf) is between 3 mm and 10mm at transition gait portion (state c). In a more preferred embodiment,this distance is between 4 mm and 9 mm. In a most preferred embodiment,this distance is between 4 and 8 mm. In one embodiment, this distance isapproximately 4.5 mm. In another embodiment, this distance isapproximately 7.5 mm.

FIG. 3 is a right elevation view of a midsole portion of one embodimentof the reactive shoe. Specifically, midsole 170 is shown comprising shoemidsole exterior upper edge 172 and shoe midsole interior upper edge174. Also depicted is shoe outsole 160 comprising shoe outsole thickness162. Shoe outsole 160 is depicted with shoe outsole first distance x₁defined along a longitudinal axis of midsole 170 and shoe and beginningfrom the distal or heel end of outsole. Shoe outsole has totallongitudinal distance of shoe outsole second distance x₂. Shoe outsolehas shoe outsole height y defined at the proximal or toe end of outsole.

In one embodiment, shoe outsole first distance x₁ as a percentage ofshoe outsole second distance x₂ is between 25% and 55%. In a morepreferred embodiment, shoe outsole first distance x₁ as a percentage ofshoe outsole second distance x₂ is between 30% and 55%. In a mostpreferred embodiment, shoe outsole first distance x₁ as a percentage ofshoe outsole second distance x₂ is between 30% and 50%.

In one embodiment, shoe outsole first distance x₁ as a percentage ofshoe outsole second distance x₂ is about 40%.

In one embodiment, shoe outsole height y as a percentage of shoe outsolesecond distance x₂ is between 10% and 25%. In a more preferredembodiment, shoe outsole height y as a percentage of shoe outsole seconddistance x₂ is between 12% and 20%. In a most preferred embodiment, shoeoutsole height y as a percentage of shoe outsole second distance x₂ isbetween 12% and 18%.

In one embodiment, shoe outsole height y as a percentage of shoe outsolesecond distance x₂ is approximately 16%.

Any of several means may be used to achieve the offset described. In oneembodiment, the offset is achieved by way of the geometry of the midsoleand/or midsole/outsole combination (collectively, the “shoe bottomarea”). That is, the geometry of the shoe bottom area is such that afirst portion (of two portions), beginning at the rear or heel area ofthe shoe, is generally planar and/or flat, and the second of twoportions curves away from the ground beginning at a point at least atthe midpoint of the shoe bottom area, if not even closer to the heel orrear of the shoe than the midpoint. Stated another way, when the shoealone (i.e. the shoe when not worn) is placed on a flat surface, therear of first portion rests on the ground for only 50% or less of thetotal longitudinal length of the shoe, and the remaining (second)portion of the shoe does not rest on the ground but instead curves awayfrom the ground. Such a geometry enables the dynamic offsetfunctionality or functionalities described.

Alternatively or in combination, the offset may be achieved by midsoleand/or midsole/outsole combinations with different material properties,e.g. different elasticity properties and geometric properties. Forexample, Example A1-13 details cross-sectional views of themidsole/outsole areas of different geometric and material properties,thereby providing different elasticity properties that may enable theafore-mentioned dynamic offset functions.

In one embodiment, an outsole is connected to the midsole comprising acentral portion, a medial portion and a lateral portion, the medialportion and the lateral portion forming a substantially non-smoothsurface, the central portion forming a substantially smooth surface witha curvilinear edge. In one embodiment, the medial portion of the outsoleis of greater lateral distance to the closest edge of the centralportion than the lateral portion is of lateral distance to its closestedge of the central portion, in the ball-of-foot region of the outsoleand/or the front 50% of the outsole. In one embodiment, the medialportion of the outsole is of approximately equal distance to the closestedge of the central portion to that of the lateral portion is of lateraldistance to its closest edge of the central portion, in the heel regionof the outsole and/or the back 50% of the outsole. In one embodiment,the dimensions of Example A2 (a figure draw to scale, with dimensions inmm), are used to define the geometries of the lateral, central andmedial portions of the outsole and/or outsole/midsole.

As referenced above, “offset” refers to the distance between portions ofthe bottom surface of the wearer's foot and the ground. Specifically,offset is the difference between the wearer's heel height above theground compared to the wearer's ball-of-foot height above the ground.For example, most shoes are designed to put the heel height 5 mm to 15mm above the ball-of-foot height. This is often determined by measuringthe total thickness of the shoe sole (outsole, midsole, lastingmaterial, and insole) in the center of the heel and at the ball-of-foot.With flat-soled shoes, the distance between the wearer's heel and theground and the ball of the wearer's foot and the ground are generallyequal, which provides an offset of about zero.

The offset of the shoe can affect the wearer's posture and the angles atwhich the wearer's foot and lower leg assume during the stride. The bodyposture and the angles between the foot and lower leg can impact thefunctioning of the muscles and joints that control the body's motion. Abare foot running or walking on a flat surface can be used as areference. A barefoot would experience zero offset when the heel andball-of-foot are on the flat surface. In the stride sequence the footgoes from zero offset while the heel and ball-of-foot are both in groundcontact to a positive offset as the heel lifts off the ground in thepropulsion phase of the stride. When the heel and ball-of-foot remain atthe same offset, the offset can be said to be “static” and not changing.Therefore, barefoot running or walking exhibits a static offset. Shoesare generally designed with static offsets that range between zero mmand 15 mm. However, some shoes, such as from the brand Earthshoes®, havebeen designed with a negative offset, often referred to as a “negativeheel”.

A static offset causes the motion of the foot during the stride to pausebriefly from the moment of initial ground contact until heel-lift andpropulsion. This brief pause is often referred to as the “stance” phaseof the stride. A pause in the motion of the foot during the stride, nomatter how brief, reduces the smoothness of the motion and can increasethe shock experienced by the forefoot. Eliminating the pause creates asmoother sensation and reduces the shock. A rigid rocker-soled shoe caneliminate this pause by literally rocking the foot as a whole from heelto toe during the stride. The present invention is not to be confusedwith a rocker-soled shoe.

Force plate data reveals the pause in motion of a static offset shoe.Using mathematical techniques to calculate the center of pressure (COP),the velocity of the center of pressure (COPV), and the acceleration ofthe center of pressure (COPA) it becomes apparent that as runners cometo stance, their COP can even reverse and move toward the heel. For thecenter of pressure to move in a negative direction, the COPV mustreverse and become negative before returning to positive during thepropulsion phase. The COPA required to make the COPV negative isreferred to as the breaking phase.

Conversely the COP of shoes with dynamic offset moves smoothly forwardalong the axis of the foot. The dynamic offset sole demonstrates noreversal in COPV. The dynamic offset enhances the running experience ofall runners as well as wearers that employ a mid-foot striking gait.

Embodiments provide a shoe that mitigates if not eliminates the pause inthe foot's motion by creating a continuously changing offset for thefoot called a dynamic offset. The dynamic offset shoe allows the foot toassume one offset at the beginning of the stride, and then tocontinuously increase that offset through the propulsion phase. This isaccomplished, in one embodiment, by allowing the foot to force theforward half of the shoe downward as the center of force on the footmigrates from the rear portion of the foot forward. The shoe sole mustnecessarily bend downward in the forward half of the shoe under thepressure of the forefoot, thus changing the shape of the sole. Bycontrast, a rocker-soled shoe maintains most, if not all, of its rockershape throughout the stride.

Regarding FIGS. 1 a-d, it is important to note that the foot position atinitial ground contact is immaterial to the function and design of theshoe 100, that is the dynamic offset motion function(s).

One embodiment of the present invention provides a shoe that places thewearer's foot in a position with an offset of 1 mm at the moment in thestride when the force on the foot is centered in the rear half of thefoot (i.e. the “loading” phase). The offset gradually increases to 4.5mm as the center of force under the foot moves toward the toes (i.e. the“transition” phase). The offset continuously increases after thetransition phase through to toe-off.

In one embodiment, the dynamic offset is achieved through the precisedimensions and shapes of the sole materials. Broadly speaking, thevertical dimensions of the sole under the rear half of the foot arealmost constant from the middle of the heel to the midfoot point, andthen decrease in a smooth fashion from the midfoot to the toe. Althoughmost shoes decrease the vertical dimension of the sole in the forefoot,there are two critical differences between a dynamic offset shoe andother shoes in one embodiment, i.e.: 1) a dynamic offset shoe has a rearportion with a relatively constant vertical dimension (relative to thetaper in the forefoot), and 2) a dynamic offset shoe tapers the verticalsole dimension of the shoe beginning at the midfoot rather than at theball-of-foot as in other shoes.

One of skill in the art will appreciate that the outsole/midsole treadsmay be fashioned in any form to provide the desired contactcharacteristics between the sole and the contemplated surface ofoperation. That is, road tread patterns are generally smoother thantrail tread pattern, which may also include nubs or other stiffeningmembers to help dig into loose or uneven ground. Further, it is oneaspect of the present invention to provide a sole that has variousstiffening characteristics. More specifically, the sole in someembodiments are neutrally balanced wherein the shoe is stiffened alongthe longitudinal axis thereof. In another embodiment, the sole is madefor individuals that pronate, wherein additional stiffness is providedadjacent to the medial heel portion of the shoe. These techniques arewell known in the art and can be employed in combination with theembodiments of the present invention shown and described herein.

In one embodiment, to provide a minimum offset during mid-foot strike,the sole of one embodiment of the present invention is angled upwardly.More specifically, the toe portion of this embodiment is angled relativeto the heel portion and mid-foot portion of the shoe by way of a curveto provide a sole that has a linear portion and a portion angledrelative thereto. One of skill in the art will appreciate that atransition portion between the mid foot portion and the toe portion mayalso be angled relative to the heel portion. In one embodiment of thepresent invention, the length of the linear portion is between about30-50% of the total horizontal length of the sole as measured from thetip of the toe to the heel. The length of the linear portion of oneembodiment is about 40% of the total length of the sole. In someembodiments of the present invention an end of the linear portion isspaced from the heel such that the heel is spaced or angled from theground a predetermined amount.

EXAMPLE

Without intending to limit the scope of the invention, Example A1-A13depicts one example construction of one embodiment of the invention indrawings each to scale. Dimensions are in millimeters.

Examples A1-A3 depicts respective lateral, bottom, and medial views ofthe outsole/midsole portion of one embodiment of the invention. ExamplesA5-A6 depict respective toe and heel views of the outsole/midsole ofExamples A1-3. Example A4 depicts a generally longitudinalcross-sectional view along axis Section A-A′ of Example A2. ExamplesA7-A12 depict sequential cross-sectional views of insole/midsole ofExamples A1-3.

Note different materials and different geometries of Examples A7-A12.For example, the material of upper left to lower right cross-sectionmarkings (the dominant material of Example A7) is of a first material(here, CMEVA), the material with lower left to upper right cross-sectionmarkings (the mid-upper portion of Example A7) is of a second material(here, VGB), and two mid-bottom portions (with no cross-sectionmarkings) are of a third material (here, semi-blown rubber). These samemappings of markings to material apply to Examples A8-A10. In ExamplesA11-12, while the upper left to lower right cross-section markings (thedominant material of Examples A11-12) is of the first material (here,CMEVA) and the portions with no markings (at mid bottom portion ofExamples A11-12) are of the third material (here, semi-blown rubber),the material with lower left to upper right cross-section markings (thelower left bottom portions of Examples A11-12) is of a fourth material(here, carbon rubber). Note that CMEVA is Compression Molded Ethyl VinylAcetate.

As will be appreciated, it would be possible to provide for somefeatures of the inventions without providing others.

To provide further clarity to the Detailed Description provided hereinin the associated drawings, the following list of components andassociated numbering are provided as follows:

Reference No. Component  10 Ground  20 Leg  22 Foot  24 Toes  26Ball-of-Foot  28 Arch  30 Heel 100 Shoe 110 Shoe Upper 120 ShoreForefoot 130 Shoe Heel Portion 140 Shoe Lateral Portion 150 Shoe MedialPortion 160 Shoe Outsole 162 Shoe Outsole Thickness 164 Shoe OutsoleNominal Traction Pattern 166 Shoe Outsole S-wave Pattern 170 ShoeMidsole 172 Shoe Midsole Exterior Upper Edge 174 Shoe Midsole InteriorUpper Edge CP_(h) Axis of Center of Pressure-Heel CP_(bf) Axis of Centerof Pressure-Ball-of-Foot D_(h-a) Distance to Heel-state a D_(bf -a)Distance to Ball-of-Foot-state a D_(h-b) Distance to Heel-state bD_(bf-b) Distance to Ball-of-Foot-state b D_(h-c) Distance to Heel-statec D_(bf-c) Distance to Ball-of-Foot-state c D_(h-d) Distance toHeel-state d D_(bf-d) Distance to Ball-of-Foot-state d x₁ Shoe OutsoleFirst Distance x₂ Shoe Outsole Second Distance y Shoe Outsole Height

While various embodiment of the present disclosure have been describedin detail, it is apparent that modifications and alterations of thoseembodiments will occur to those skilled in the art. However, it is to beexpressly understood that such modifications and alterations are withinthe scope and spirit of the present disclosure, as set forth in thefollowing claims.

The foregoing discussion of the disclosure has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the disclosure to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of thedisclosure are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed disclosurerequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of thedisclosure.

Moreover, though the present disclosure has included description of oneor more embodiments and certain variations and modifications, othervariations and modifications are within the scope of the disclosure,e.g., as may be within the skill and knowledge of those in the art,after understanding the present disclosure. It is intended to obtainrights which include alternative embodiments to the extent permitted,including alternate, interchangeable and/or equivalent structures,functions, ranges or steps to those claimed, whether or not suchalternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

What is claimed is:
 1. An article of footwear comprising: an upperattachable to a foot of a user; and a midsole connected to the uppercomprising a first portion proximate a heel of the foot and a secondportion proximate a ball-of-foot of the foot, the heel of the foothaving a heel center of pressure imparted to the first portion anddefining a first distance between the heel center of pressure and theground, and a ball-of-foot center of pressure imparted to the secondportion and defining a second distance between the ball-of-foot centerof pressure and the ground, wherein a distance offset of the firstdistance minus the second distance is increased between a loading gaitphase and a toe off gait phase.
 2. The article of footwear of claim 1,wherein the first portion is generally of constant thickness and thesecond portion is generally of decreasing thickness along a longitudinalaxis of the midsole from the heel to the ball-of-foot.
 3. The article offootwear of claim 2, wherein the first portion is 30-50% of a totaldistance of the longitudinal axis of the midsole.
 4. The article offootwear of claim 3, wherein the first portion is interconnected to thesecond portion.
 5. The article of footwear of claim 2, wherein thedecreasing thickness generally forms a French curve.
 6. The article offootwear of claim 1, wherein the distance offset is always positivebetween the loading gait phase and the toe off gait phase.
 7. Thearticle of footwear of claim 1, wherein the distance offset at the toeoff gait phase is at least 40 mm.
 8. The article of footwear of claim 1,wherein the distance offset of the first distance minus the seconddistance is continuously increased between the loading gait phase andthe toe off gait phase.
 9. The article of footwear of claim 1, wherein afoot center of pressure imparted to the midsole continuously increasesbetween the loading gait phase and the toe off gait phase.
 10. A methodof manufacturing an article of footwear comprising: forming an upperattachable to a foot of a user; and forming a midsole connected to theupper comprising a first portion proximate a heel of the foot and asecond portion proximate a ball-of-foot of the foot, the heel of thefoot having a heel center of pressure imparted to the first portion anddefining a first distance between the heel center of pressure and theground, and a ball-of-foot center of pressure imparted to the secondportion and defining a second distance between the ball-of-foot centerof pressure and the ground, wherein a distance offset of the firstdistance minus the second distance is increased between a loading gaitphase and a toe off gait phase.
 11. The method of claim 10, wherein thefirst portion is generally of constant thickness and the second portionis generally of decreasing thickness along a longitudinal axis of themidsole from the heel to the ball-of-foot.
 12. The method of claim 10,wherein the first portion is 30-50% of a total distance of thelongitudinal axis of the midsole and the first portion is interconnectedto the second portion.
 13. The method of claim 10, wherein the distanceoffset is always positive between the loading gait phase and the toe offgait phase.
 14. The method of claim 10, wherein the distance offset atthe toe off gait phase is at least 40 mm.
 15. The method of claim 10,wherein the distance offset of the first distance minus the seconddistance is continuously increased between the loading gait phase andthe toe off gait phase.
 16. The method of claim 10, wherein a footcenter of pressure imparted to the midsole continuously increasesbetween the loading gait phase and the toe off gait phase.
 17. Themethod of claim 10, wherein the midsole is manufactured using injectionmolding.
 18. An athletic shoe, comprising: an upper attachable to a footof a user; and a midsole connected to the upper comprising a firstportion generally of constant thickness proximate a heel of the foot anda second portion generally of decreasing thickness along a longitudinalaxis of the midsole from the heel to the ball-of-foot and proximate aball-of-foot of the foot, the first portion 30-50% of a total distanceof the longitudinal axis of the midsole and interconnected to the secondportion, the heel of the foot having a heel center of pressure impartedto the first portion and defining a first distance between the heelcenter of pressure and the ground, and a ball-of-foot center of pressureimparted to the second portion and defining a second distance betweenthe ball-of-foot center of pressure and the ground, wherein a distanceoffset of the first distance minus the second distance is continuouslyincreased between a loading gait phase and a toe off gait phase and isalways positive between the loading gait phase and the toe off gaitphase.
 19. The article of footwear of claim 18, wherein a foot center ofpressure imparted to the midsole continuously increases between theloading gait phase and the toe off gait phase.
 20. The article offootwear of claim 18, wherein the distance offset at the toe off gaitphase is at least 40 mm.
 21. An article of footwear comprising: an upperattachable to a foot of a user; a midsole connected to the uppercomprising a first portion proximate a heel of the foot and a secondportion proximate a ball-of-foot of the foot; and an outsole connectedto the midsole comprising a central portion, a medial portion and alateral portion, the medial portion and the lateral portion forming asubstantially non-smooth surface, the central portion forming asubstantially smooth surface with a curvilinear edge.
 22. The article offootwear of claim 21, wherein the heel of the foot having a heel centerof pressure imparted to the first portion and defining a first distancebetween the heel center of pressure and the ground, and a ball-of-footcenter of pressure imparted to the second portion and defining a seconddistance between the ball-of-foot center of pressure and the ground,wherein a distance offset of the first distance minus the seconddistance is increased between a loading gait phase and a toe off gaitphase.
 23. The article of footwear of claim 21, wherein the centralportion is of a first material and the medial and lateral portions areof a second material.
 24. The article of footwear of claim 21, whereinthe central portion extends over and is integral to at least one of atoe portion and a heel portion of the article of footwear.